QUIC: fixed ngx_http_test_reading() for QUIC streams. Previously this function generated an error trying to figure out if client shut down the write end of the connection. The reason for this error was that a QUIC stream has no socket descriptor. However checking for eof is not the right thing to do for an HTTP/3 QUIC stream since HTTP/3 clients are expected to shut down the write end of the stream after sending the request. Now the function handles QUIC streams separately. It checks if c->read->error is set. The error flags for c->read and c->write are now set for all streams when closing the QUIC connection instead of setting the pending_eof flag.

--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -3022,6 +3022,19 @@ ngx_http_test_reading(ngx_http_request_t
 
 #endif
 
+#if (NGX_HTTP_QUIC)
+
+    if (c->qs) {
+        if (c->read->error) {
+            err = 0;
+            goto closed;
+        }
+
+        return;
+    }
+
+#endif
+
 #if (NGX_HAVE_KQUEUE)
 
     if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {